In general, a through hole for injecting a packing material is formed in a packing cylinder for an expansion joint.
In one example, a packing cylinder for an expansion joint is coupled to a stuffing box (packing box) forming a space between two pipes overlapping each other in a joint apparatus for flexibly connecting various fluid transport pipes. A through hole of a packing cylinder for an expansion joint communicates with an inside of a stuffing box such that a packing material can be injected into the inside of the stuffing box. When injection of the packing material is completed, a plunger is coupled to a packing cylinder for an expansion joint to close or seal the through hole such that it is able to prevent the packing material from leaking.
A related prior art technique is disclosed in Korean Patent Registration Publication No. 10-0834849 (Registered on May. 28, 2008, Title of invention: Packing cylinder for expansion contraction joint apparatus).